Photo by Pete Marovich/Getty Images(WASHINGTON) -- Two weeks have passed since the United States and its partners reached a sweeping, if tentative, nuclear deal with Iran despite the opposition of Israel’s government. At a Middle East policy conference on Saturday, President Obama was asked what made the Iran deal “different” when compared to the failed nuclear agreements pursued by Presidents Reagan with Pakistan and Clinton with North Korea.

“Well, we don’t know yet. We don’t know yet.” Obama said at the Brookings Institute’s Saban Forum. “I think it's important for everybody to understand: This is hard, because the technology of the nuclear cycle you can get off the internet. The knowledge of creating a nuclear weapon is already out there.”

The president was responding to a question from the sit-down discussion’s moderator, Haim Saban, and acknowledged there was a possibility Iran would renege on its side of the bargain.

“Having said that, by the time we had gotten an agreement with North Korea they essentially already had a nuclear weapon. With respect to Pakistan there was never the kinds of inspection regimes and international sanctions and UN resolutions that have been in place,” Obama continued, adding the failsafe mechanisms around the current deal were "unprecedented and unique” in diplomatic precedent.

The Saban Forum leans heavily toward Israeli policy and comes amid tension between the Washington and Tel Aviv over the deal. At the time of its signing, Israeli Prime Minister Benjamin Netanyahu, scheduled to speak at the forum by satellite on Sunday, called it a “historic mistake” and one that made the world a “much more dangerous place.” Critics in the US and Israel have said Tehran could use the six-month agreement, in which the US eases some economic sanctions while the Middle East state pauses its nuclear program, to buy time. Further, the endgame of the agreement, if successful, would allow Iran to retain a nuclear energy program with low uranium enrichment levels for power plants. But skeptics fear that even that infrastructure could be rapidly modified to produce weaponized product – what is called “breakaway” capability.

“If we could create an option in which Iran eliminated every single nut and bolt of their nuclear program, and forswore the possibility of ever having a nuclear program, and for that matter got rid of all its military capabilities I would take it,” Obama said. “But, Haim, I want to make sure that everybody understands that particular option is not available.”

President Obama also had cautious optimism for his Iranian counterpart, President Hassan Rouhani.

“Obviously Rouhani is part of the Iranian establishment and the -- I think we have to assume that his ideology is one that is hostile to the United States and to Israel,” he said. “But what he also represents is the desire on the part of the Iranian people for a change of direction. And we should not underestimate or entirely dismiss a shift in how the Iranian people want to interact with the world.”

“We have to not constantly assume that it's not possible that Iran, like any country, can change over time,” the president would later add.

Secretary of State John Kerry and Israeli Foreign Minister Avigdor Lieberman also spoke at the forum. Meanwhile, Obama’s discussion with Haim Saban also comes two weeks after the president attended a high-end Democratic fundraiser at Saban’s Beverly Hills home. Saban, an Israeli-American media mogul and top-dollar donor for the party, hosted the fundraiser on November 25th, two days after the nuclear deal was struck in Geneva.